Dungeon Portal

This is like solo leveling but without the characters and the system (but you can add them if you want to), for anyone who doesn't know solo leveling there is a portal to a dungeon where there is magical monsters that even modern weapons can kill but some people evolves to a hunter (E(lowest) to S (the highest)) and have the ability to kill these magical monsters they now make weapons designed to kill them, when you enter a portal you have to defeat the boss to close the portals (they have the same rankings E (easy to defeat) and a S (only a strike team that at least have 1 S rank can to enter)), the portals appear everywhere and if the portal is left undefeated for a week (7 days) there will be a dungeon break where all of the monsters come out and you need to defeat the boss to close. Good luck